I use Wilton fondant. Just can’t beat the price with coupons at Michaels. I can get a 5lb box for $10 rather then spending over $20 for the same amount of satin ice. I also love how easy to use the Wilton fondant is. I rarely have problems with cracking like I do in satin ice and their new black and red colored fondant is just a life saver.
As for shortening I use butter flavor crisco in all my buttercreams and regular crisco for use with fondant. Never had any problems or complaints with them and they are easy to find at most grocery stores.